The In Vitro And In Vivo Anti-acute Monocytic Leukemia Cell Effect Of Mimic Manganese Superoxide Dismutase

ObjectTo study inhibition effect and primary anti-tumor mechanisms of Mimic manganese superoxide dismutase on U937 acute monocytic leukemia cells in vitro and vivo.Methods1. MTT assay was used to observe the anti-proliferation effect of Mn SODm.2. Annexin V-PE/7-ADD staining assay and H33258 fluorescent staining assay were seperately adopted to observe apoptosis rate and morphological changes of U937 cells.3. Expressions of apoptosis related proteins include caspase-8, caspase-9, caspase-3, Bcl-2,Bad, cytosol cyto-c and mitochondria cyto-c were detected with western blotting assay.4. Transplantation tumor models of U937 cell were established on nude mice to observe anti-leukemia effect of Mn SODm in vivo. Tumor volumes, body weights, final tumor weight and inhibitinon rate of different groups were measured to observe the anti-tumor effect of Mn SODm in vivo.All in vitro experiments were performed under different concertrations of Mn SODm.Results1. The results of MTT assay show that the proliferation rate of Mn SODm treated U937 cell has lower proliferation rate than control group(P< 0.05). Mn SODm markedly reduced the proliferation rate of U937 cell in a dose and time-dependent manner(P< 0.05).2. The apoptosis rate and morphological changes rate of U937 cells which treated with Mn SODm obviously higher than that of control group(P< 0.05). The apoptosis induction effects of Mn SODm performes in a dose-dependent manner(P< 0.05).3.Western blotting results show that the level of pro-apoptosis proteins include cleaved-caspase-8, cleaved-caspase-9, cleaved-caspase-3, Bad, and cytosol cyto-c were enhanced and anti-apoptosis proteins include Bcl-2 and mitochondria cyto-c were decreased in a dose-dependent manner.4. Tumor weight of Mn SODm treated group less than that control group(P < 0.05);5. No significant difference of body weight between Mn SODm treated group and control group was found(P > 0.05). No toxicity sings were found in nude mice treated with Mn SODm.ConclusionMn SODm could inhibit proliferation and induce apoptosis on U937 acute monocytic leukemia cells in a time and dose-dependent manner. Mitochondrial apoptosis pathway was involved in anti-tumor mechanism of Mn SODm. Transplantation tumors growth was significantly inhibited by Mn SODm in vivo. Mn SODm is expected to be developed as an effective anti-tumor agent in the future.